Simulation of building evacuation with different ratios of the elderly considering the influence of obstacle position

The elderly ratio in the world’s population is increasing and countries are facing ongoing challenges in improving the safety of elderly pedestrians. It is of vital importance to organize the evacuation of elderly pedestrians effectively under emergencies. In this study, the simulation parameters of Pathfinder and GCFM (generalized centrifugal-force model) are set according to the results of the control experiment. Through comparison, it can be found that the simulation results of Pathfinder are more consistent with the experimental results. As the elderly ratio increases, the evacuation time required gets longer. The evacuation time of the sub room which is closer to the floor exit is longer. The flow rate of the crowd with 100% elderly will be 26.72% lower than that of the crowd with 0% elderly. With the obstacle getting closer to the exit, the evacuation efficiency decreases more significantly. Placing an obstacle more than 5 m away from the exit can significantly reduce its effects. Compared with adults, the elderly form a larger congestion area and higher density in front of the obstacle. The obstacle in the corridor can buffer the density pressure of the exit and it is more obvious when it is closer to the exit. Correspondingly, the pedestrian speed at the exit gets higher under lower density. This study can be reference for the building evacuation of the population with different elderly ratios. It can be guidance for the placement of the obstacles in the corridor, such as information desk, temperature measuring desk in the epidemic environment.